core: migrate to dankgo shared go modules, embed quickshell in DMS

binary to mount at runtime, -c or DMS_SHELL_DIR overrides required to
explicitly override embedded configuration

core/cmd/dms/server_client.go

@@ -101,11 +101,8 @@ func getServerSocketPath() string {
 		runtimeDir = os.TempDir()
 	}
 
-	if parentPID, ok := sessionParentPID(os.Getenv("WAYLAND_DISPLAY")); ok {
-		sessionSock := filepath.Join(runtimeDir, fmt.Sprintf("danklinux-%d.sock", parentPID))
-		if _, err := os.Stat(sessionSock); err == nil {
-			return sessionSock
-		}
+	if sessionSock, ok := shellApp.SessionSocketPath(); ok {
+		return sessionSock
 	}
 
 	entries, err := os.ReadDir(runtimeDir)